Symptoms.—It is scarcely necessary to enter Into the question of the symptoms of hydatid cyst. It usually affects the liver, and manifests itself as a swelling which gradually enlarges so as to cause a projection of some part of the belly. It may occasion symptoms of dyspepsia, or, by pressing on and obstructing the bile ducts, produce jaundice, or by pressing on blood-vessels cause dropsy, piles, &c.
Treatment.-- No medicine can destroy the hydatid nor arrest its growth. What can be done is to puncture the tumour and draw off the fluid by means of a fine tube. This, of course, is a question and procedure for a sur geon. If an examination of the fluid by the microscope shows the presence of booklets (as shown in Fig. 115, d, p. 258), which have been detached from the echinococcus heads, the nature of the tumour is evident.
The Prevention of Tape-worm.—The prevention of hydatid may be disposed of first. It has been noted that the seeds of the para site are obtained from the dog, and that where dogs are not kept " it is well-nigh impossible that the disease should be contracted." Where dogs are kept, care and cleanliness•should re move all risk of disease. A dog affected with tape-worm should receive physic at intervals. Dr. Cobbold advises that its excreta should be burned, and that boiling-hot water should occasionally be thrown over the floors of all kennels where dogs are kept. The eggs are destroyed by the heat of boiling water. If there is any risk of them getting into drinking water, it should be boiled before use. To im prove its taste afterwards it should be shaken up with air. Careful filtering through a char coal filter will keep back the seeds. The filter should not be used too long without heating, to destroy ova that have been retained by it.
The prevention of other forms of tape-worm may also be secured by care and cleanliness. As we have seen, the common tape-worms are derived from measled beef or pork, and if one eats no measled beef or pork no danger is in curred. But one cannot always be sure that no measles exist in the meat one is eating, and it is of the utmost consequence to know whether there is any method of securing that any bladder or cyst worm that meat may contain is destroyed before it is eaten, so that it becomes unable to produce the mature tape-worm. There is such
a method, and it is by heat. The cysticercus of the beef or pork tape-worm cannot survive a temperature of 140° Fahr. continued for five minutes. That temperature is considerably be low the boiling-point (212° Fahr.). This has been made quite certain by the experiments of an Italian, Dr. Perroncito, who submitted the cysts to various temperatures, and who found them die when they were heated up to 120° or 130° Fahr. His results were proved by some students, who, of their own free-will, swallowed some so heated, but were never affected with tape-worm.
A sufficient degree of heat, then, kills the measles of veal, beef, or pork. It is, therefore, certain that meat properly and thoroughly cooked cannot occasion tape-wo•m. It must be noticed that to destroy measles in meat the meat must be heated through and through to the proper temperature. The outside of the meat might be heated sufficiently, but the inside not nearly enough, so that measles in the deep parts would escape. This ought, therefore, to be watched in the cooking of any large piece of meat. Minced meat and sausages ought to receive special attention.
Another danger must be avoided. A cook who has cut up meat containing measles may harbour them on her hands. She may cook the meat properly enough, but in serving it up, if she has not previously washed her hands, may introduce the parasite on to the plates; or if a cook uses the knife, with which the uncooked meat has been cut up, to serve the food up for dinner, without cleaning it properly, the cystic worm may be conveyed to the cooked food.
It seems that measles in cattle have no very long term of existence. Dr. Cobbold has shown that an animal with measles is cured naturally, by the death of the parasites, after the lapse of ten months. Beyond that term the cysticerci do not live; they (lie and are subject to chalk like degeneration. Cattle known to be measled should, therefore, be sent to some place where there is no chance of them getting a fresh in fection, and should be kept there for eight to ten months. At the end of that time, if they have not meanwhile received a fresh supply, it would not be possible for their flesh to produce tape-worm, even though it were undercooked before being eaten.